This study investigated the bonding nature and electrostatic potential of asymmetric Li ionic mobility in Li2B4O7 crystals using the maximum entropy method (MEM) combined with Rietveld refinement and Ewald's technique. Compared with the interaction between oxygen and boron, Li+ ions exhibited weak interactions with both oxygen and boron. Furthermore, electrostatic-potential-distribution analysis showed that Li+ ions had a much weaker interaction with the matrix along the c-axis channel, suggesting that higher ionic conductivity occurred along the c-axis than along the a- and b-axes. (C) 2010 Elsevier B.V. All rights reserved.